Controlled Trial

A large number of epidemiologic studies have suggested that a diet high in fruits, vegetables, and other foods derived from plants is associated with a lower risk of cancer ( 1 – 8). Antioxidant nutrients such as ascorbic acid, -tocopherol, and the carotenoids (eg, beta carotene) that are present in plant-derived foods may have a major preventive role against carcinogenesis ( 9), and it has been sug-gested that they may suppress tumor cell growth and induce tumor cell apoptosis ( 10 – 12). Antioxidants also counterbalance the pro-duction of reactive oxygen species (ROS), which may cause oxida-tive damage to cells and modify cell growth regulatory pathways, leading to enhanced risk for carcinogenesis ( 13 – 15). Over the past three decades, numerous clinical trials ( 16 – 30) have evaluated the effi cacy of antioxidants and minerals, used sin-gly or in various combinations, in the prevention of cancers and other chronic diseases. However, their fi ndings have been incon